Sourcing renewable power: what to know about GaN

DigiKey’s supplier business development manager, wireless and IoT, Josh Mickolio

DigiKey’s supplier business development manager, wireless and IoT, Josh Mickolio, explains how WBG semiconductors are providing a path to smarter, more efficient power design.

The renewable energy sector has seen significant design activity over recent years. It is accelerating the use of wide bandgap (WBG) devices—specifically gallium nitride (GaN)-based power solutions—to increase capacity, allow for more efficient conversion and most importantly, allow for a sustainable future as silicon becomes harder to come by.

Wide bandgap production has increasingly hit higher capacity and more companies are introducing or expanding their offerings. However, capacity around GaN, GaN- on-silicon and GaN-on-silicon carbide (SiC) products is still in short supply because overall fab capacity remains limited. This means in a smaller environment, even a small change can impact the supply chain.

GaN provides faster switching speed, smaller size, higher efficiency and a lower cost. However, it also adds a new level of complexity to power designs and bills- of-materials. You almost always need to make changes or find a suitable second source to support differentcomponents. WBG devices add a layer of complexity with identifying and testing compatible PFCs and gate drivers. You must look at other device attributes, layout and PCB design. This is nothing new in power design but engineers may not be as familiar with simulations and some parasitic elements introduced by inefficient layout and higher frequency operation.

A few requirements and attributes to be aware of when considering GaN:

• Layout considerations: minimizing or accounting for parasitics at different operational frequencies

• Component selection: this is always important but identifying devices that are compatible vs those that offer performance benefits
• Thermal design: WBG devices have differing thermal properties, especially on traditional FR4 material
• EMI performance: higher switching speeds and parasitics require thorough EMI review and noise isolation

The difficulty in finding suitable second source materials in a BoM can be alleviated by using a multi-footprint design and providing for more scalability in the surrounding design and architecture. Design flexibility is key to keeping the supply chain healthy in the long-term while ensuring designs are future proofed.

WBG-based power solutions are enabling everything from micro-inverters and optimisers to solar energy storage systems and more efficient e-mobility charging stations, all with the benefit of reducing size and long-term costs.

A lot of interesting design work is happening with GaN and SiC devices which will only accelerate electrical vehicle development and charging systems, as well as exciting use cases in smart utilities, microgrids and storage/ load management systems. The renewable energy sector will continue to impact our lives in many ways and WBG semiconductors are providing a path to the next generation of smarter, more efficient power designs.